Related Party Transactions	12 Months Ended
Dec. 31, 2021
Related Party Transactions [Abstract]
Related Party Transactions	Note 17. Related party transactions Erasca Foundation In May 2021, the Company established the Erasca Foundation to provide support such as direct research grants, hardship grants, patient advocacy, patient education in underserved populations, and funding for other initiatives to positively impact society that align with the Company’s mission. The Company's chief executive officer and certain board members serve as directors of the Erasca Foundation and the Company's chief executive officer, chief financial officer, and general counsel are also officers of the Erasca Foundation. In July 2021, the Company issued 1,093,557 shares of its common stock to the Erasca Foundation as a contribution and recorded $17.5 million as a contribution of common stock to the Erasca Foundation in the consolidated statements of operations and comprehensive loss. In December 2021, the Company loaned the Erasca Foundation $100,000 in exchange for a non-interest bearing promissory note that matures one year following the date of the note. As of December 31, 2021, $100,000 is recorded as a receivable in prepaid expenses and other current assets in the consolidated balance sheet. Disgorgement of stockholder's short-swing profits In August 2021, the Company received $553,000 related to the recovery of short-swing profits from a private investment fund affiliated with one of its board members, a related party, under Section 16(b) of the Securities Exchange Act of 1934, as amended. The Company recognized these proceeds as a capital contribution from a stockholder with an increase to additional paid-in-capital in its consolidated balance sheet and as cash provided by financing activities in its consolidated statement of cash flows.

Related Party Transactions

12 Months Ended

Dec. 31, 2021

Note 17. Related party transactions

Erasca Foundation

In May 2021, the Company established the Erasca Foundation to provide support such as direct research grants, hardship grants, patient advocacy, patient education in underserved populations, and funding for other initiatives to positively impact society that align with the Company’s mission. The Company's chief executive officer and certain board members serve as directors of the Erasca Foundation and the Company's chief executive officer, chief financial officer, and general counsel are also officers of the Erasca Foundation. In July 2021, the Company issued 1,093,557 shares of its common stock to the Erasca Foundation as a contribution and recorded $17.5 million as a contribution of common stock to the Erasca Foundation in the consolidated statements of operations and comprehensive loss. In December 2021, the Company loaned the Erasca Foundation $100,000 in exchange for a non-interest bearing promissory note that matures one year following the date of the note. As of December 31, 2021, $100,000 is recorded as a receivable in prepaid expenses and other current assets in the consolidated balance sheet.

Disgorgement of stockholder's short-swing profits

In August 2021, the Company received $553,000 related to the recovery of short-swing profits from a private investment fund affiliated with one of its board members, a related party, under Section 16(b) of the Securities Exchange Act of 1934, as amended. The Company recognized these proceeds as a capital contribution from a stockholder with an increase to additional paid-in-capital in its consolidated balance sheet and as cash provided by financing activities in its consolidated statement of cash flows.